Table below is based on 76 patients with Anti-Xa levels >1.0.
Characteristic
Conventional (n=50)
Non-conventional (n=26)
Total (n=76)
P-value
Age (y)at the time of result: N(%)
0.48
Missing
0 (0.0)
0 (0.0)
0 (0.0)
<=65 years
21 (42.0)
8 (30.8)
29 (38.2)
>65 years
29 (58.0)
18 (69.2)
47 (61.8)
Age (y)at the time of result: N(%)
0.30
Missing
0 (0.0)
0 (0.0)
0 (0.0)
<=65 years
21 (42.0)
8 (30.8)
29 (38.2)
>65 to <=80 years
21 (42.0)
10 (38.5)
31 (40.8)
>80 years
8 (16.0)
8 (30.8)
16 (21.1)
BMI: N(%)
0.02
Missing
5 (10.0)
0 (0.0)
5 (6.6)
<30
16 (32.0)
15 (57.7)
31 (40.8)
30 - 40
22 (44.0)
4 (15.4)
26 (34.2)
>40
7 (14.0)
7 (26.9)
14 (18.4)
Estimated Glomerular filtration rate (mL/min)in the 24 h prior to the level: N(%)
0.31
Missing
0 (0.0)
0 (0.0)
0 (0.0)
>=30 mL/min
41 (82.0)
24 (92.3)
65 (85.5)
<30 mL/min
9 (18.0)
2 (7.7)
11 (14.5)
modified CG (mL/min): N(%)
0.88
Missing
0 (0.0)
0 (0.0)
0 (0.0)
<30 mL/min
8 (16.0)
4 (15.4)
12 (15.8)
30-50 mL/min
11 (22.0)
8 (30.8)
19 (25.0)
>50-80 mL/min
19 (38.0)
9 (34.6)
28 (36.8)
>80 mL/min
12 (24.0)
5 (19.2)
17 (22.4)
Model 1.1: LMWH ~ individualised dose, CrCl, age, weight
Model specifications - Outcome: LMWH level - Covariates: individualised dose, modified CrCl, age, weight - Model: Multiple linear regression     Anti-Xa level ~ individualised dose + modified CrCl + age + weight
Bodyweight
Global test
model term
df1
df2
F.ratio
p.value
individualised_dose_used
1
287
8.228
0.004
modified_cg
1
287
0.019
0.9
age
1
287
0.613
0.4
weight
1
287
3.454
0.06
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.418 (-0.785, -0.051)
0.03
individualised_dose_usedNon-conventional
-0.135 (-0.228, -0.043)
0.004
modified_cg
0.000 (-0.001, 0.002)
0.9
age
0.002 (-0.002, 0.005)
0.4
weight
0.001 (-0.000, 0.003)
0.06
Model diagnostics
Results
Overall
Contrast
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
0.873 (0.796, 0.958)
0.004
Adjusted means (95% CI)
individualised_dose_used
response
SE
df
lower.CL
upper.CL
Conventional
0.833
0.027
287
0.782
0.888
Non-conventional
0.727
0.024
287
0.681
0.777
Modified CrCl
Contrast
modified_cg
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
60
0.873 (0.796, 0.958)
0.004
(Non-conventional) / Conventional
61
0.873 (0.796, 0.958)
0.004
Bodyweight
Contrast
weight
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
93
0.873 (0.796, 0.958)
0.004
(Non-conventional) / Conventional
94
0.873 (0.796, 0.958)
0.004
Age
Contrast
age
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
66
0.873 (0.796, 0.958)
0.004
(Non-conventional) / Conventional
67
0.873 (0.796, 0.958)
0.004
BMI
Global test
model term
df1
df2
F.ratio
p.value
individualised_dose_used
1
273
7.675
0.006
modified_cg
1
273
0.019
0.9
age
1
273
0.299
0.6
bmi
1
273
4.836
0.03
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.409 (-0.810, -0.007)
0.05
individualised_dose_usedNon-conventional
-0.134 (-0.230, -0.039)
0.006
modified_cg
-0.000 (-0.002, 0.002)
0.9
age
0.001 (-0.003, 0.005)
0.6
bmi
0.005 (0.001, 0.009)
0.03
Model diagnostics
Results
Overall
Contrast
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
0.874 (0.795, 0.962)
0.006
Adjusted means (95% CI)
individualised_dose_used
response
SE
df
lower.CL
upper.CL
Conventional
0.830
0.028
273
0.777
0.887
Non-conventional
0.726
0.025
273
0.679
0.776
Modified CrCl
Contrast
modified_cg
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
60
0.874 (0.795, 0.962)
0.006
(Non-conventional) / Conventional
61
0.874 (0.795, 0.962)
0.006
BMI
Contrast
bmi
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
29
0.874 (0.795, 0.962)
0.006
(Non-conventional) / Conventional
30
0.874 (0.795, 0.962)
0.006
Age
Contrast
age
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
66
0.874 (0.795, 0.962)
0.006
(Non-conventional) / Conventional
67
0.874 (0.795, 0.962)
0.006
Model 1.2(Sensitivity analysis): LMWH ~ individualised dose, CrCl, age, weight
Sensitivity analysis: Records with once-daily dosing excluded.
Model specifications - Outcome: LMWH level - Covariates: individualised dose, modified CrCl, age, weight - Model: Multiple linear regression     Anti-Xa level ~ individualised dose + modified CrCl + age + weight
Bodyweight
Global test
model term
df1
df2
F.ratio
p.value
individualised_dose_used
1
227
10.472
0.001
modified_cg
1
227
0.760
0.4
age
1
227
0.489
0.5
weight
1
227
4.097
0.04
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.347 (-0.780, 0.086)
0.1
individualised_dose_usedNon-conventional
-0.170 (-0.274, -0.067)
0.001
modified_cg
-0.001 (-0.003, 0.001)
0.4
age
0.002 (-0.003, 0.006)
0.5
weight
0.002 (0.000, 0.003)
0.04
Model diagnostics
Results
Overall
Contrast
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
0.843 (0.760, 0.936)
0.001
Adjusted means (95% CI)
individualised_dose_used
response
SE
df
lower.CL
upper.CL
Conventional
0.860
0.031
227
0.802
0.923
Non-conventional
0.725
0.027
227
0.674
0.781
Modified CrCl
Contrast
modified_cg
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
60
0.843 (0.760, 0.936)
0.001
(Non-conventional) / Conventional
61
0.843 (0.760, 0.936)
0.001
Bodyweight
Contrast
weight
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
93
0.843 (0.760, 0.936)
0.001
(Non-conventional) / Conventional
94
0.843 (0.760, 0.936)
0.001
Age
Contrast
age
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
66
0.843 (0.760, 0.936)
0.001
(Non-conventional) / Conventional
67
0.843 (0.760, 0.936)
0.001
BMI
Global test
model term
df1
df2
F.ratio
p.value
individualised_dose_used
1
215
9.812
0.002
modified_cg
1
215
1.583
0.2
age
1
215
0.104
0.7
bmi
1
215
4.681
0.03
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.276 (-0.773, 0.220)
0.3
individualised_dose_usedNon-conventional
-0.170 (-0.277, -0.064)
0.002
modified_cg
-0.001 (-0.004, 0.001)
0.2
age
0.001 (-0.004, 0.006)
0.7
bmi
0.005 (0.000, 0.010)
0.03
Model diagnostics
Results
Overall
Contrast
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
0.843 (0.757, 0.939)
0.002
Adjusted means (95% CI)
individualised_dose_used
response
SE
df
lower.CL
upper.CL
Conventional
0.857
0.032
215
0.796
0.922
Non-conventional
0.723
0.027
215
0.671
0.779
Modified CrCl
Contrast
modified_cg
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
60
0.843 (0.757, 0.939)
0.002
(Non-conventional) / Conventional
61
0.843 (0.757, 0.939)
0.002
BMI
Contrast
bmi
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
29
0.843 (0.757, 0.939)
0.002
(Non-conventional) / Conventional
30
0.843 (0.757, 0.939)
0.002
Age
Contrast
age
Ratio of Geometric means (95% CI)
P-value
(Non-conventional) / Conventional
66
0.843 (0.757, 0.939)
0.002
(Non-conventional) / Conventional
67
0.843 (0.757, 0.939)
0.002
Model 2.1: Risk of supratherapeutic LMWH levels
Model specifications - Outcome: LMWH level >1.0 (yes/no) - Covariates: individualised dose, dosing frequency, modified CrCl, age, weight - Model: Logistic regression     Anti-Xa level ~ individualised dose + dosing frequency + modified CrCl + age + weight
In-range vs out-of-range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
1.151
1
0.3
modified_cg
1.752
1
0.2
age
0.287
1
0.6
bmi
0.026
1
0.9
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
0.360 (-1.742, 2.461)
0.7
individualised_dose_usedNon-conventional
-0.275 (-0.777, 0.228)
0.3
modified_cg
-0.006 (-0.015, 0.003)
0.2
age
-0.006 (-0.027, 0.016)
0.6
bmi
0.002 (-0.021, 0.025)
0.9
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.76 (0.46, 1.26)
0.3
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.76 (0.46, 1.26)
0.3
(Non-conventional) / Conventional
61
0.76 (0.46, 1.26)
0.3
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.76 (0.46, 1.26)
0.3
(Non-conventional) / Conventional
30
0.76 (0.46, 1.26)
0.3
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.76 (0.46, 1.26)
0.3
(Non-conventional) / Conventional
67
0.76 (0.46, 1.26)
0.3
In-range vs below range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
2.876
1
0.09
modified_cg
0.266
1
0.6
age
0.094
1
0.8
bmi
5.184
1
0.02
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
0.047 (-3.277, 3.370)
1.0
individualised_dose_usedNon-conventional
0.660 (-0.115, 1.435)
0.10
modified_cg
-0.004 (-0.017, 0.010)
0.6
age
-0.005 (-0.039, 0.028)
0.8
bmi
-0.048 (-0.093, -0.002)
0.04
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
1.94 (0.89, 4.20)
0.09
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
1.94 (0.89, 4.20)
0.09
(Non-conventional) / Conventional
61
1.94 (0.89, 4.20)
0.09
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
1.94 (0.89, 4.20)
0.09
(Non-conventional) / Conventional
30
1.94 (0.89, 4.20)
0.09
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
1.94 (0.89, 4.20)
0.09
(Non-conventional) / Conventional
67
1.94 (0.89, 4.20)
0.09
In-range vs above range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
6.430
1
0.01
modified_cg
1.775
1
0.2
age
0.120
1
0.7
bmi
2.484
1
0.1
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.503 (-2.856, 1.850)
0.7
individualised_dose_usedNon-conventional
-0.766 (-1.370, -0.162)
0.01
modified_cg
-0.007 (-0.017, 0.003)
0.2
age
-0.004 (-0.029, 0.020)
0.7
bmi
0.020 (-0.005, 0.045)
0.1
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.46 (0.25, 0.85)
0.01
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.46 (0.25, 0.85)
0.01
(Non-conventional) / Conventional
61
0.46 (0.25, 0.85)
0.01
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.46 (0.25, 0.85)
0.01
(Non-conventional) / Conventional
30
0.46 (0.25, 0.85)
0.01
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.46 (0.25, 0.85)
0.01
(Non-conventional) / Conventional
67
0.46 (0.25, 0.85)
0.01
In-range vs above range (>1.2)
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
0.689
1
0.4
modified_cg
0.014
1
0.9
age
1.788
1
0.2
bmi
0.658
1
0.4
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-3.641 (-6.932, -0.350)
0.03
individualised_dose_usedNon-conventional
-0.318 (-1.073, 0.437)
0.4
modified_cg
0.001 (-0.013, 0.015)
0.9
age
0.022 (-0.011, 0.056)
0.2
bmi
0.014 (-0.019, 0.046)
0.4
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.73 (0.34, 1.55)
0.4
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.73 (0.34, 1.55)
0.4
(Non-conventional) / Conventional
61
0.73 (0.34, 1.55)
0.4
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.73 (0.34, 1.55)
0.4
(Non-conventional) / Conventional
30
0.73 (0.34, 1.55)
0.4
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.73 (0.34, 1.55)
0.4
(Non-conventional) / Conventional
67
0.73 (0.34, 1.55)
0.4
Model 2.2(Sensitivity analysis): Risk of supratherapeutic LMWH levels
Sensitivity analysis: Records with once-daily dosing excluded.
Model specifications - Outcome: LMWH level >1.0 (yes/no) - Covariates: individualised dose, dosing frequency, modified CrCl, age, weight - Model: Logistic regression     Anti-Xa level ~ individualised dose + dosing frequency + modified CrCl + age + weight
In-range vs out-of-range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
1.067
1
0.3
modified_cg
1.631
1
0.2
age
0.162
1
0.7
bmi
0.377
1
0.5
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
0.292 (-2.375, 2.959)
0.8
individualised_dose_usedNon-conventional
-0.304 (-0.883, 0.275)
0.3
modified_cg
-0.008 (-0.020, 0.004)
0.2
age
-0.005 (-0.032, 0.021)
0.7
bmi
0.008 (-0.017, 0.032)
0.5
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.74 (0.41, 1.32)
0.3
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.74 (0.41, 1.32)
0.3
(Non-conventional) / Conventional
61
0.74 (0.41, 1.32)
0.3
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.74 (0.41, 1.32)
0.3
(Non-conventional) / Conventional
30
0.74 (0.41, 1.32)
0.3
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.74 (0.41, 1.32)
0.3
(Non-conventional) / Conventional
67
0.74 (0.41, 1.32)
0.3
In-range vs below range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
4.132
1
0.04
modified_cg
0.176
1
0.7
age
0.004
1
1.0
bmi
4.421
1
0.04
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.925 (-5.035, 3.185)
0.7
individualised_dose_usedNon-conventional
0.974 (0.009, 1.940)
0.05
modified_cg
0.004 (-0.014, 0.021)
0.7
age
-0.001 (-0.042, 0.039)
1.0
bmi
-0.051 (-0.104, 0.002)
0.06
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
2.65 (1.01, 6.96)
0.05
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
2.65 (1.01, 6.96)
0.05
(Non-conventional) / Conventional
61
2.65 (1.01, 6.96)
0.05
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
2.65 (1.01, 6.96)
0.05
(Non-conventional) / Conventional
30
2.65 (1.01, 6.96)
0.05
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
2.65 (1.01, 6.96)
0.05
(Non-conventional) / Conventional
67
2.65 (1.01, 6.96)
0.05
In-range vs above range
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
6.600
1
0.01
modified_cg
3.390
1
0.07
age
0.089
1
0.8
bmi
3.985
1
0.05
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.211 (-3.232, 2.810)
0.9
individualised_dose_usedNon-conventional
-0.889 (-1.587, -0.192)
0.01
modified_cg
-0.013 (-0.027, 0.001)
0.07
age
-0.005 (-0.035, 0.025)
0.8
bmi
0.028 (0.001, 0.055)
0.05
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.41 (0.20, 0.83)
0.01
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.41 (0.20, 0.83)
0.01
(Non-conventional) / Conventional
61
0.41 (0.20, 0.83)
0.01
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.41 (0.20, 0.83)
0.01
(Non-conventional) / Conventional
30
0.41 (0.20, 0.83)
0.01
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.41 (0.20, 0.83)
0.01
(Non-conventional) / Conventional
67
0.41 (0.20, 0.83)
0.01
In-range vs above range (>1.2)
Global test
LR Chisq
Df
Pr(>Chisq)
individualised_dose_used
1.008
1
0.3
modified_cg
0.522
1
0.5
age
1.774
1
0.2
bmi
1.212
1
0.3
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-3.579 (-7.617, 0.459)
0.08
individualised_dose_usedNon-conventional
-0.434 (-1.289, 0.421)
0.3
modified_cg
-0.007 (-0.025, 0.012)
0.5
age
0.027 (-0.013, 0.067)
0.2
bmi
0.020 (-0.015, 0.055)
0.3
Results
Overall
Contrast
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
0.65 (0.28, 1.52)
0.3
Modified CrCl
Contrast
modified_cg
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
60
0.65 (0.28, 1.52)
0.3
(Non-conventional) / Conventional
61
0.65 (0.28, 1.52)
0.3
BMI
Contrast
bmi
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
29
0.65 (0.28, 1.52)
0.3
(Non-conventional) / Conventional
30
0.65 (0.28, 1.52)
0.3
Age
Contrast
age
Odds ratios (95% CI)
P-value
(Non-conventional) / Conventional
66
0.65 (0.28, 1.52)
0.3
(Non-conventional) / Conventional
67
0.65 (0.28, 1.52)
0.3
Model 3.1: LMWH levels ~ Enoxaparin dose (mg)
Overall
Model specifications - Outcome: LMWH level - Covariates: enoxaparin dose, modified CrCl, age, weight - Model: Multiple linear regression (with non-linear terms for enoxaparin dose) Â Â Â Â Anti-Xa level ~ enoxaparin dose + modified CrCl + age + weight
Global test
model term
df1
df2
F.ratio
p.value
enox_dose
1
225
15.580
0.0001
modified_cg
1
225
7.111
0.008
age
1
225
1.547
0.2
weight
1
225
11.572
0.0008
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-0.644 (-1.100, -0.187)
0.006
ns(enox_dose, 3)1
0.845 (0.590, 1.100)
<0.0001
ns(enox_dose, 3)2
1.874 (1.301, 2.447)
<0.0001
ns(enox_dose, 3)3
1.207 (0.727, 1.688)
<0.0001
modified_cg
-0.002 (-0.004, -0.001)
0.008
age
0.003 (-0.001, 0.007)
0.2
weight
-0.004 (-0.006, -0.002)
0.0008
Model diagnostics
Estimated marginal means
Enoxaparin dose used (mg)
Estimated LMWH level
SE
df
Lower 95% CI
Upper 95% CI
25
0.38
0.05
225
0.30
0.48
60
0.66
0.03
225
0.60
0.72
80
0.82
0.03
225
0.77
0.87
100
0.95
0.04
225
0.88
1.03
200
1.70
0.37
225
1.11
2.61
Post-hoc comparisons
NOTE: Ratio of Geometric means for every 10 unit increase in Enoxaparin dose.
Contrast
Ratio of Geometric means (95% CI)
P-value
enox_dose90 / enox_dose80
1.084 (1.035, 1.134)
0.0006
By dosing strategy
Model specifications - Outcome: LMWH level - Covariates: enoxaparin dose, dosing strategy, modified CrCl, age, weight - Model: Multiple linear regression (with non-linear terms for enoxaparin dose) Â Â Â Â Anti-Xa level ~ enoxaparin dose + dosing strategy + enoxaparin dose*dosing strategy+ modified CrCl + age + weight
NOTE: Ratio of Geometric means for every 10 unit increase in Enoxaparin dose.
Contrast
individualised_dose_used
Ratio of Geometric means (95% CI)
P-value
enox_dose90 / enox_dose80
Conventional
1.080 (1.028, 1.133)
0.002
enox_dose90 / enox_dose80
Non-conventional
1.093 (1.039, 1.150)
0.0006
Model 3.2: LMWH levels ~ Enoxaparin dose (mg/kg)
Overall
Model specifications - Outcome: LMWH level - Covariates: enoxaparin dose (mg/kg), modified CrCl, age - Model: Multiple linear regression (with non-linear terms for enoxaparin dose) Â Â Â Â Anti-Xa level ~ enoxaparin dose + modified CrCl + age
Global test
model term
df1
df2
F.ratio
p.value
enox_dose_mgkg
1
226
10.788
0.001
modified_cg
1
226
2.708
0.1
age
1
226
0.246
0.6
Model summary
Var
Coefficients (95% CI)
P-value
(Intercept)
-1.014 (-1.553, -0.475)
0.0003
ns(enox_dose_mgkg, 3)1
0.716 (0.454, 0.978)
<0.0001
ns(enox_dose_mgkg, 3)2
1.861 (0.993, 2.729)
<0.0001
ns(enox_dose_mgkg, 3)3
0.955 (0.377, 1.534)
0.001
modified_cg
-0.002 (-0.003, 0.000)
0.1
age
0.001 (-0.003, 0.005)
0.6
Model diagnostics
Estimated marginal means
Enoxaparin dose (mg/kg)
Estimated LMWH level
SE
df
Lower 95% CI
Upper 95% CI
0.20
0.35
0.07
226
0.24
0.52
0.78
0.76
0.03
226
0.70
0.83
0.95
0.84
0.02
226
0.80
0.89
1.00
0.86
0.03
226
0.81
0.92
2.10
1.31
0.37
226
0.75
2.27
Post-hoc comparisons
NOTE: Ratio of Geometric means for every 0.1 mg/kg increase in Enoxaparin dose.
Contrast
Ratio of Geometric means (95% CI)
P-value
enox_dose_mgkg1 / enox_dose_mgkg0.9
1.046 (0.994, 1.100)
0.08
By dosing strategy
Model specifications - Outcome: LMWH level - Covariates: enoxaparin dose (mg/kg), dosing strategy, modified CrCl, age - Model: Multiple linear regression (with non-linear terms for enoxaparin dose) Â Â Â Â Anti-Xa level ~ enoxaparin dose + dosing strategy + enoxaparin dose*dosing strategy+ modified CrCl + age
NOTE: Ratio of Geometric means for every 0.1 mg/kg increase in Enoxaparin dose.
Contrast
individualised_dose_used
Ratio of Geometric means (95% CI)
P-value
enox_dose_mgkg1 / enox_dose_mgkg0.9
Conventional
1.161 (1.004, 1.344)
0.04
enox_dose_mgkg1 / enox_dose_mgkg0.9
Non-conventional
1.029 (0.966, 1.097)
0.4
Brief conclusion
Overall, dosing strategy has an effect on LMWH levels (both as a continuous measure, and whether LMWH is above range), where patients on non-conventional dose have a lower LMWH level on average.
[Model 1] Patients on non-conventional dose has, on average, 13% lower [Ratio of Geometic means 0.87 (95% CI 0.79 - 0.96)] in mean LMWH levels compared to those who were on conventional dose.
[Model 1.2] Sensitivity analysis with once-daily dosing excluded showed similar results, where patients on non-conventional dose has, on average, 16% lower [Ratio of Geometric means 0.84 (95% CI 0.76 - 0.94)] in mean LMWH levels compared to those who were on conventional dose.
[Model 2] There is a 54% decrease [Odds ratio 0.46 (95% CI 0.25 - 0.85)] in the risk of LMWH levels being >1.0 (vs in-range) for patients on non-conventional dose, compared to those who were on conventional dose.
[Model 3] There is a slight increase in the average LMWH level with increasing Enoxaparin dose. For every 10 unit increase in Enoxaparin dose, there is (on average) a 6.3% increase in the conventional dose [Ratio of Geometric means 1.063 (95% CI 1.019 - 1.108)]. Alhtough there is statsitical significance, the magnitude of effect is small and the difference may not be clinically meaningful.